This invention relates to a chip-type circuit element mounting apparatus adapted to handle a chip-type circuit element storing package of a disc-like shape provided therein with a spirally continuous path for receiving chip-type circuit elements therein, and more particularly to a chip-type circuit element mounting apparatus for mounting a chip-type circuit element on a printed circuit board while picking up, by means of a camera, an image of a chip-type circuit element held on a chip mounting head through a chip suction nozzle.
In a conventional chip-type circuit element mounting apparatus (hereinafter referred to as "chip mounting apparatus") which is adapted to mount a chip-type circuit element (hereinafter referred to as "chip") on a printed circuit board, a chip observing camera is fixedly arranged on the side of a body of the chip mounting apparatus, Such arrangement requires to move a chip mounting head to a position of the chip observing camera and then temporarily stop it at the position or pass it through the position at a predetermined speed in order to pick up an image of a chip held on the chip mounting head through a chip suction nozzle attached to the chip mounting head.
Unfortunately, temporary stoppage of the chip mounting head at the position of the chip observing camera or passage of the former through the latter at a predetermined speed leads to a problem of reducing a speed at which the chip is mounted on the printed circuit board.
Also, a lighting unit required for observing an image of a chip mounted on the chip mounting head through the chip suction nozzle by image processing is divided into two types. One of them is so constructed that a reflection plate is arranged behind the chip suction nozzle to reflect light emitted by the lighting unit, wherein the light is horizontally or upwardly directed to the reflection plate. The other type includes an illuminant arranged behind the suction nozzle.
The prior art permits an outer diameter of the chip suction nozzle of the chip mounting apparatus to be set to be smaller than an outer configuration of a chip, to thereby prevent the chip suction nozzle from interfering with picking-up of an image of a chip through a camera.
However, recent microminiaturization of a chip causes manufacturing of a chip suction nozzle having an outer diameter smaller than a size of the chip to be highly difficult. When an outside dimension of a distal end surface of the suction nozzle exceeds that of a chip held on the chip suction nozzle, an inner side of a contour of the distal end surface of the chip suction nozzle forms a shadow as well, resulting in proper observation of an image of the chip held on the chip suction nozzle being highly difficult.
The assignee proposed a chip mounting apparatus in which a chip storage package of a disc-like configuration is held in a feeder section. The chip storage package is formed therein with a spirally continuous packing path in which a number of chips are stored in a row. The chip storage package provides good replaceability, therefore, use of the chip storage package in the feeder section permits an chip-free or empty chip storage package to be readily replaced with a new chip storage package filled with chips, to thereby ensure continuous feeding of chips from the feeder section to the chip mounting head. This leads to continuous running of the chip mounting apparatus over a long period of time without causing shortage of chips.
When the chip storage package received in the feeder section of the chip mounting apparatus is emptied of chips, it is required to execute an operation of removing the empty chip storage package from the feeder section to return it to an empty chip storage package collecting space of a stocker section and an operation of removing a new chip storage package filled with chips from the stocker section to feed it to the feeder section in order. Thus, a disadvantage of requiring much time for replacement of the chip storage package is encountered with the conventional chip mounting apparatus.
Further, in the case that various kinds of chip storage packages are arranged in the feeder section of the chip mounting apparatus, it is required to identify, on a side of a chip storage package replacement means, a type of chips stored in each of the chip storage packages when it is carried out to remove an empty chip storage package from the feeder section and feed a new chip storage package filled with chips from the stocker section to the feeder section. Thus, it is highly desirable to develop a means of readily and positively identifying a type of chips stored in each of chip storage packages.
In addition, the conventional chip mounting apparatus is generally constructed in such a manner that a height of a chip is detected to control downward movement of the chip mounting head for mounting of the chip on a printed circuit board depending on the height, to thereby render a pressure applied to chips different in height constant. However, such controlling of downward movement of the chip mounting head is deteriorated due to a variation in height of the printed circuit board due to warpage or twist of the board or the like, leading to unexpected damage to chips.